Active sites of beta-lactamases from Bacillus cereus.

Philos Trans R Soc Lond B Biol Sci

Published: May 1980

There are two extracellular beta-lactamases produced by Bacillus cereus 569. One of these enzymes, beta-lactamase I, is inactivated by 6-beta-bromopenicillanic acid: the site of reaction is serine-44. This is a conserved amino acid residue in the other beta-lactamases whose structures have been determined, and it becomes a good candidate for an active-site group in these enzymes. The inactivation may involve a rearrangement leading to a dihydrothiazine. The other extracellular enzyme produced by B. cereus, beta-lactamase II, is exceptional in requiring metal ions for activity. The Zn II and Co II enzymes (the former is more active) have been studied by nuclear magnetic resonance, and by absorption spectroscopy. The groups that bind the metal ion required for activity are three histidine residues and the enzyme's sole thiol group.

Download full-text PDF

Source
http://dx.doi.org/10.1098/rstb.1980.0050DOI Listing

Publication Analysis

Top Keywords

bacillus cereus
8
active sites
4
sites beta-lactamases
4
beta-lactamases bacillus
4
cereus extracellular
4
extracellular beta-lactamases
4
beta-lactamases produced
4
produced bacillus
4
cereus 569
4
569 enzymes
4

Similar Publications

Growing interests in replacing conventional preservatives and antibiotics in food and pharmaceutical industries have driven the exploration of bacterial metabolites, especially those from strains with generally recognized as safe (GRAS) status, such as lactic acid bacteria (LAB). In this study, a supernatant cocktail derived from multiple LAB strains was prepared and its bioactivities-antimicrobial, antibiofilm, antioxidant, cytotoxicity, and stability-were thoroughly investigated. The cocktail's main components were identified using thermal and protease treatments, gas chromatography coupled to mass spectrometry (GC-MS), and flame ionization detection (GC-FID).

View Article and Find Full Text PDF
Article Synopsis
  • The study investigates how well a gut bacteria strain, Bacillus cereus AP-01, can break down low-density polyethylene (LDPE), using experiments over 28 days to measure its effectiveness.
  • The researchers employed various methods like FTIR and SEM to analyze changes in LDPE structure and confirmed the bacterial strain through molecular characterization.
  • Results showed that the bacteria significantly degraded LDPE, with a 30.3% weight loss and changes in mechanical properties, highlighting its potential as a solution for plastic pollution.
View Article and Find Full Text PDF

(Gaertn) Roxb. and Retz. are significant botanicals in ancient Ayurvedic medicine.

View Article and Find Full Text PDF

Butachlor is a widely utilized acetamide herbicide noted for its systemic selectivity against pre-emergence grass weeds. Butachlor has negative effects on organisms and the environment, so it is necessary to screen degradation strains. In this investigation, strain DC-1 was isolated from soil persistently exposed to butachlor.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!